The detailed analysis of RNA polymerase III virally coded RNA products will be performed using the most sensitive biochemical techniques available. A general technique will be used to obtain adenovirus mutants for specific areas of the genome. Mutants in the low molecular weight RNA genes will be isolated and characterized at different levels of host permissiveness, ranging from productive infection to cell transformation. The primary objectives are: a. to characterize the role of the virus coded low molecular weight RNAs in virus dvelopment, and b. to analyze the regulation of the expression of the genes coding for these low molecular weight RNAs.